Standardized uptake values (SUV) of 18F-fluorodeoxyglucose in six brain regions in house sparrow females with empty implants (n = 5), estradiol implants (E2, n = 10), or empty implants ~1 month after having an estradiol implant (post-E2; n = 5) in response to house sparrow (HOSP) or white-throated sparrow (WTSP) song.

These six regions were included in our analysis because they contain areas previously associated with auditory perception and song recognition. See Table 1 for statistical results from linear mixed models.